These studies represent a continuation of the work on the influence of adrenergic nerves on the motility of the rabbit oviduct, and will proceed along three lines: 1. We will measure the turnover rate of norepinephrine (NE) in oviducts isolated from castrate, estrogen-treated and estrogen plus progesterone-treated rabbits. Turnover will be measured by inhibiting the r synthesis of NE with alpha-methyl-p-tyrosine and measuring the decline in NE content in the oviduct as a function of time. Atrial muscle will be used as a 'control' muscle. Since the turnover rate of the transmitter reflects the degree of nervous activity, the results of these studies should indicate whether the ovarian hormones influence tonic nervous discharge to the oviducts. 2. We will begin experiments on the effects of adrenergic nerve stimulation on the electrical activity of the rabbit oviduct in vitro. In these experiments membrane resting and action potentials will be recorded with inracellular microelectrodes in the smooth muscle cells of the oviduct during stimulation of the perivascular (adrenergic nerves). Oviducts from the groups of animals listed in 1 will be studied. 3. We will study the influence of stretch on the response of the castrate oviduct to nerve stimulation. Since castration is usually folloed by muscle atrophy and since stretching the muscle may prevent this atrophy, these expriments may distinguish between hormonal and physical factors in control of the muscle. BIBLIOGRAPHIC REFERENCES: Kroeger, E.A., J.M. Marshall, and C.P. Bianchi. Effect of D-600 and isoproterenol on calcium movements in rat myometrium. J. Pharmacology and Exptl. Therapeutics, 193: 309-316, 1975. Reiner, O. and J.M. Marsall. Action of D-600 on spontaneous and electrically stimulated activity of the parturient rat uterus. Naunyn-Sch. Arch. Pharmacol., 209: 21-28, 1975.